JPH10151685A - Bead lock device in tire molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance various capacities of a pneumatic tire produced while bead roundness is ensured by using a bead lock member constituted of an annular rubber material, having an almost rectangular cross-sectional shape, having a bead receiving recessed part formed to the head part thereof and having at least one or more reinforcing layer provided to the leg part thereof. SOLUTION: A bead lock member 10 holding beads of a cylindrical green tire is constituted of an annular rubber material and the JIS (A) hardness of the rubber material is pref. 80 or more and the min. elongation thereof is pref. 140%. The bead lock member 10 has an almost rectangular cross-sectional shape and has a bead receiving recessed part formed to the head part thereof and at least one reinforcing layer 13, for example, the reinforcing layer having a four-layered structure is provided to the leg part 12 thereof. The reinforcing layer 13 is constituted by laterally embedding cord reinforcing materials 14, 14... composed of steel cords and arranged on the periphery of the bead lock member 10. An attaching hole is provided to the main shaft of a tire molding machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bead lock device in a tire forming machine for holding a bead of a cylindrical green tire with a bead lock member when forming a green tire.

[0002]

2. Description of the Related Art Conventionally, when forming a toroidal green tire from a cylindrical green tire, a bead lock device in a tire forming machine that holds a bead of a cylindrical green tire with a bead lock member includes, for example, The one shown in FIGS. 3 and 4 is known.

[0003] That is, as shown in FIGS. 3 and 4, in a tire molding machine, a rubber pladder 2 in a tire molding drum attached to a main shaft (not shown) is air-tightly held by a pladder clamp ring 3 and a pladder restraint 4. An annular bead lock member 5 composed of divided steel bead lock segments 5a, 5a,... For holding a bead Wa of a cylindrical green tire W is disposed on the outside. Are formed at the heads of the divided bead lock segments 5a, 5a,... Which hold the arc-shaped beads Wa.
are configured to expand and contract in the tire radial direction.

[0004] However, since the structure for holding the bead is a divided bead lock segment 5a made of steel, as shown in FIG. There is a problem that securing the degree is insufficient. Further, the divided bead lock segments 5a,
There is a problem that air is generated between segments due to insufficient holding between 5a.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and aims to solve the problem.
An object of the present invention is to provide a bead lock device in a tire forming machine capable of improving various performances and the like of a pneumatic tire manufactured while securing roundness of a bead when held.

[0006]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems of the prior art, the present inventor has obtained a bead lock device for a tire molding machine of the above object by using a bead lock member having a specific structure. They succeeded and completed the present invention. That is, the bead lock device in the tire molding machine of the present invention includes the following (1) to
(3). (1) The bead lock device in the tire forming machine according to the present invention is the bead lock device in a tire forming machine that holds a bead of a cylindrical green tire with a bead lock member when forming a green tire. Is formed of an annular rubber material, and has a substantially rectangular cross-sectional shape, a bead receiving recess formed in the head,
The leg portion is provided with at least one or more reinforcing layers. (2) The bead lock device for a tire molding machine according to the above (1), wherein the annular rubber material has a JIS (A) hardness of 80 or more and a minimum elongation of 140%. (3) The reinforcing layer is composed of two to four reinforcing layers.
A bead lock device in the tire molding machine according to (1) or (2). (4) The bead lock device for a tire molding machine according to any one of the above (1) to (3), wherein the reinforcing layer comprises a reinforcing layer in which a cord reinforcing material is embedded in a width direction. (5) The above-mentioned cord reinforcement is made of steel cord.
The bead lock device in the tire molding machine according to any one of (1) to (4).

[0007]

Embodiments of the present invention will be described below in detail. The present invention has a feature in a bead lock member, and the bead lock member of the present invention replaces the bead lock member 5 shown in FIG. 3 which is a conventional example (current equipment).

FIGS. 1 and 2 show an example of a main part of an embodiment of the present invention. Reference numeral 10 denotes a bead lock member for holding a bead of a cylindrical green tire. The bead lock member 10 is made of an annular rubber material. The rubber material is not particularly limited, but preferably has a JIS (A) hardness of 80 or more and an elongation of MIN.
It is desirable to have 140% (minimum).

As shown in FIG. 1, the bead lock member 10 has a substantially rectangular cross section and has a concave portion 11 for receiving a bead on its head.
Is formed, and the leg portion 12 is provided with a reinforcing layer 13 having a four-layer structure. The reinforcing layer 13 is formed by embedding cord reinforcing members 14, 14,... Made of steel cords in the width direction, and is disposed around the bead lock member 10 as shown in FIG. Reference numeral 15 denotes a mounting hole that is mounted on the main shaft of the tire molding machine 1 (not shown).

In the bead lock device in the tire molding machine of the present embodiment configured as described above, since the bead lock member 10 has an annular lock ring structure, the bead portion is beaded as compared with the conventional steel lock segment. The entire surface can be held by the lock member 10, the roundness of the bead portion can be ensured when the bead is held, and the uniformity is improved. In addition, since there is no gap between the segments at the time of bead holding, product defects are improved, and various performances of the manufactured pneumatic tire can be improved. Further, since the bead lock member 10 is made of a rubber material, the air sealing property with the tire bead portion can be improved, and since the bead lock member 10 is reinforced by the reinforcing layer 13, the bead lock member 10 has the same strength as conventional steel. Furthermore, since the bead lock member of the tire molding machine of the existing equipment can be replaced, there is an advantage that the existing equipment can be effectively used.

The bead lock device in the tire molding machine of the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the reinforcing layer 13 has a four-layer structure, but the reinforcing layer can be configured as an arbitrary layer according to the use of the pneumatic tire to be manufactured and the like. Can achieve the purpose, preferably,
It is desirable that the reinforcing layer 13 has a two-layer to four-layer structure. In addition, although the cord reinforcement was made of steel cord,
A member using a member having strong compression rigidity may be used.

[0012]

According to the present invention, it is possible to secure roundness of the bead portion when holding the bead, so that various performances of the pneumatic tire to be manufactured can be improved, and the existing equipment can be improved. A bead lock device in a tire molding machine that can be effectively used is provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a main part of an embodiment of the present invention in a sectional form.

FIG. 2 is a front view showing an example of a main part of the embodiment of the present invention in a sectional form.

FIG. 3 is a sectional view showing an example of a bead lock device in a conventional tire molding machine.

FIG. 4A is a partial perspective view showing an example of a divided lock segment of a bead lock device in a conventional tire molding machine. (B) is a partial perspective view showing an example of a use state of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tire molding machine 10 Bead lock member 11 Bead receiving recess 12 Leg 13 Reinforcement layer 14 Cord reinforcement

Claims (5)

[Claims] 1. A bead lock device in a tire molding machine that holds a bead of a cylindrical green tire with a bead lock member when molding a green tire, wherein the bead lock member is formed of an annular rubber material, A bead lock device for a tire molding machine, wherein a cross-sectional shape is substantially rectangular, a concave portion for receiving a bead is formed in a head portion, and at least one reinforcing layer is provided in a leg portion. 2. The bead lock device according to claim 1, wherein the annular rubber material has a JIS (A) hardness of 80 or more and a minimum elongation of 140%. 3. The bead lock device for a tire molding machine according to claim 1, wherein the reinforcing layer comprises two to four reinforcing layers. 4. The bead lock device in a tire molding machine according to claim 1, wherein the reinforcing layer is formed of a reinforcing layer in which a cord reinforcing material is embedded in a width direction. 5. The bead lock device in a tire forming machine according to claim 1, wherein the cord reinforcing member is made of a steel cord.